diff --git a/api-compose-object.go b/api-compose-object.go
index 4f8d74e8c..fc5171d1b 100644
--- a/api-compose-object.go
+++ b/api-compose-object.go
@@ -455,7 +455,7 @@ func (c Client) ComposeObjectWithProgress(dst DestinationInfo, srcs []SourceInfo
 	for i, src := range srcs {
 		h := src.Headers
 		if src.encryption != nil {
-			src.encryption.Marshal(h)
+			encrypt.SSECopy(src.encryption).Marshal(h)
 		}
 		// Add destination encryption headers
 		if dst.encryption != nil {